definitions

• ecology

  the study of relationships between organisms and their environment, both abiotic and biotic
• species

  group of organisms that are genetically similar and interbreed with one another to produce fertile offspring
• population

  made up of all members of a species living in a region (given area) at the same time, this is the fourth level of biosphere
• community

  share particular habitats, limited to species that are capable of surviving the abiotic factors of that location
• lithosphere

  divided into continental crust and oceanic crust
• habitat

  place where a particular organism lives
• niche

  the role that a species plays in a community
• ecological niche

  functional term that describes either the role played by a species in the community or the total set of environmental factors that determine species distribution
• realized niche

  other organisms competing for same resources
• fundamental niche

  favorable conditions species require to survive and reproduce
• biome

  type of ecosystem characterized by distinctive climate and soil conditions and a distinctive biological community that is adapted to the specific set of conditions
• ecotone

  a transitional boundary between two ecological communities which contains characteristic species of each community
• biological community

  limited by biotic factors such as predators and food availability
• ecosystem

  comprises of all populations in a given area together with non-living components
• biosphere

  part of the earth that supports life
• atmosphere

  layer of air that surrounds the planet
• hydrosphere

  part of the earth composed of all the water on the earth
• limiting factor

  influences the distribution or population size of an organism or species
• symbiosis

  ecological relationships between two organisms of different species living closely together and forming some type of feeding relationship
• mutualism

  when two organisms of different species each benefit from the relationship
• commensalism

  one species benefits and the other is not affected
• paratism

  one of the organism in the relationship lives off the other organism, the host, harming it and sometimes causing death
• competition

  the use of a resource by one individual that reduces the availability of that resource for another individual
• intraspecific competition

  competition among members of the same species
• interspecific competition

  competition between members of different species
• predator

  an organism that gains nourishment from killing and eating other animals
• food chain

  the transfer of food energy from producers through a series of consumers, unidirectional
• food web

  complex networks of interconnected food chains at different trophic levels, allows an organism to obtain its food from more than one type of organism
• bioaccumulation

  refers to the way pollutants enter a food chain
• biomagnification

  refers to the increase of pollutants as it travels up trophic levels
• biomass

  total amount of living organic matter in an ecosystem
• ecological succession

  the process by which ecosystems change and develop over time
• primary succession

  community develops on bare uncolonized ground, no life existed previously
• pioneer species

  first to colonize bare environments
• secondary succession

  area where there is soil and where life was already present but experienced some environmental change
• climax communities

  progressive increase in biomass
• carrying capacity

  maximum population size that can be sustained by particular environment over a relatively long period of time
• species abundance

  total number of organisms found in a biological community
• species diversity

  measure of the number of different species present within a community
• species richness

  a member of the number of species found in a sample location